This invention relates to a metal single fiber-reinforced prepreg having substantially uniaxially oriented filaments dispersed in a thermosetting resin matrix.
A sheet-like prepreg is known which includes a multitude of uniaxially oriented, organic or inorganic filaments, such as of carbon fibers, glass fibers or aromatic polyamide fibers, impregnated with a thermosetting resin. Such a prepreg gives light weight composite articles having high bending strength and modulus and, thus, is utilized as raw materials for golf club shafts, fishing rods and the like molded articles.
There is still a strong demand for improved molded articles with higher mechanical properties. To comply with this demand, it is necessary to use a specific material other than the above-described fibers. Boron fibers are known to have high bending strength and modulus and are considered to be utilizable for prepregs of the above-mentioned type. However, boron fibers are single fibers having relatively a large diameter of 100-200 .mu.m and, therefore, are not suited for use as fibers for prepregs. In particular, a prepreg having boron fibers impregnated with a thermosetting resin is readily disintegrated along the axis.
To cope with this problem, a prepreg is proposed in which glass fibers are used as weft and boron fibers as warp. Also proposed is a laminate of a boron fiber prepreg with a prepreg of a glass fiber fabric (glass slim cloth). In either case, improvement in mechanical properties per unit weight of the prepreg is not satisfactory since the glass fibers oriented in the direction perpendicular to that of the boron fibers do not contribute to the improvement. In addition, these prepregs are not easily produced.